Lubricating device for lockstitch sewing machine loopers

ABSTRACT

A lubricating device for lockstitch sewing machine loopers, more particularly, for the thread case raceways of vertical axis looptaker of the rotary hook type. The restraining means for the thread case against rotation with the looptaker consist of a slot-shaped part in the bottom of the thread case and a nose cooperating with the slot-shaped port. The nose is a part of a non-rotating shaft, which is received within the tubular looper shaft. The non-rotating shaft is a pump shaft formed externally with a spiral lubricant elevating groove.

United States Patent 1 Schrudde Nov. 20, 1973 LUBRICATING DEVICE FOR LOCKSTITCH SEWING MACHINE LOOPERS [75] Inventor: Reinhold Schrudde, Milse, Germany [73] 'Assignee: Koehs Adler AG., Bielefeld, Germany 22 Filed: Nov.17,1971 21 App1.No.:199,557

[30] Foreign Application Priority Date Nov. 19, 1970 Germany P 20 56 880.3

[52] US. Cl. 112/256 [51] Int. Cl D05b 71/00 [58] Field of Search 112/256, 184, 43;

[56] References Cited UNITED STATES PATENTS 3,390,653 7/1968 Ketterer 112/184 X 2,385,288 9/1945 Vesconte et a1. 112/256 3,146,745 9/1964 Schenkengel 1 12/256 2,764,l l3 9/1956 Schaefer 1 12/256 2,346,139 4/1944 Myers '1 12/256 Primary Examiner-George l-l. Krizmanich Att0rney-Jacob L. Kollin [57] ABSTRACT A lubricating device for lockstitch sewing machine loopers, more particularly, for the thread case raceways of vertical axis looptaker of the rotary hook type. The restraining means for the thread case against rotation with the looptaker consist of a slot-shaped part in the bottom of the thread case and a nose cooperating with the slot-shaped port. The nose is a part of a nonrotating shaft, which is received within the tubular looper shaft. The non-rotating shaft is a pump shaft formed externally with a spiral lubricant elevating groove.

1 Claim, 3 Drawing Figures LUBRICATING DEVICE FOR LOCKSTITCH SEWING MACHINE LOOPERS BACKGROUND OF THE INVENTION This invention relates to a lubricant device for a rotary looptaker in double lockstitch sewing machines, in which the looptaker is carried by a driven, vertically disposed hollow looper shaft and which is provided with an inner annular raceway for receiving the bearing rib of the thread case and a locking member for restraining the thread case against rotation with the looptaker. The locking member comprises a nose which engages with a slot-shaped port formed in the bottom of the thread case, and a non-rotating shaft received in the hollow looper shaft, which carries the nose. Such a locking member for restraining the thread case against rotation with the looptaker is described in Swiss Patent No. 89,402.

There are already known devices for lubricating the raceway of rotary looptakers which are carried by a driven, vertically disposed looper shaft and in which the thread case disposed within the looptaker, is provided with a rotation-restraining lug disposed midway between thread case stops, and with a mechanical opener for providing a thread passage past the rotation restraining means by imparting an ascillation to thread case in a direction opposite to the direction of rotation of the looptaker.

It is an object of this invention to create a lubricating device for vertical axis looptakers of lockstitch sewing machines which is provided with a restraining member for the thread case, comprising a non-rotating shaft received in the hollow looper shaft and having a nose which engages with a slot-shaped port formed in the bottom of the thread case.

It is a further object of the invention to provide a lubricating device for looptakers of the above mentioned type, for lubricating the thread case raceways of said looptakers.

It is a further object of the invention to provide a lubricating device for looptakers of the above mentioned type, which will deliver an adjustable quantity of lubricant to the thread case.

SUMMARY According to the invention these objects are essentially achieved by providing the non-rotating shaft of the restraining means for the thread case with a pump shaft formed externally with a spiral lubricant elevating groove forming together with the rotating looptaker shaft a screw pump, in order to elevate oil out of the oil supply into an annular groove, which is formed in the lower part of the inner cylinder wall of the looptaker body. The annular groove is bushed with a felt ring, and between the latter and the annular raceway there is provided a wick.

Furthermore, there is provided a plug which is pivotally attached in a cylindrical bore in the bottom of the housing, and is rotatable about the non-rotating pump shaft. The plug has a grooved clearance formed at a part of the peripheral area of the plugand in the zone of a duct in the bottom of the housing, This grooved clearance is provided with a reduction of crosssectional area from a maximum sectional area at one end to a zero-sectional area at the other end of the clearance. The plug is further provided with a through bore, which terminates in the grooved clearance, for

the passage of oil to the spiral lubricant elevating groove of the pump shaft.

The pump shaft is provided with a clamp lever which is secured tothe free end of the shaft and slidably received on a pin arranged on the bottom of the housing.

The regulating means for adjusting the delivery of oil to the raceway of the cup-shaped body of the looper comprises a collar which is provided with a gasket ring and arranged on the free end of the pump shaft, and a spring situated between the collar and the clamp lever, for pressing the collar and the gasket ring against the plug, and the disk-shaped portion of the pump shaft against a plane gliding surface of the cup-shaped body of the looper.

BRIEF DESCRIPTION OF THE DRAWINGS F. 1 is a sectional view through the looper housing, the driving parts, the looptaker and the lubricating device;

FIG. 2 is a section taken along line 11-1 of FIG. 1, on an enlarged scale, and

FIG. 3 is a perspective view of the locking member, on a reduced scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT A looptaker shaft 3 carrying a rotary looptaker 4 is pivoted within ball bearings 2 which are received in a housing 1.

The inner cylinder wall 5 of the cup-shaped body 6 of the looper 4 is formed with an annular raceway 7, in which is supported a peripheral bearing rib 9 extending along the circumference of the thread case 8. In the lowr part of the inner cylinder wall 5 there is formed an annular groove 10 for receiving a felt ring 11. A borein the wall of the cup shaped body 6 is filled with a wick 12, which connects the felt ring 11 with the annular raceway 7.

A thread case restraining member 13, which consists of a plate 14 with a nose 15 formed thereon, and a nonrotating shaft 16 supported in the tubular looper shaft 3, engages with the nose 15 in a rotation restraining notch 18, in the bottom 17 of the thread case 8 in order to restrain the thread case 8 against rotation with the loptaker 4. For this purpose, a clamp lever 19 is secured to the free end of the non-rotating shaft 16 and is slidably received on a pin 20 which is arranged on the bottom of the housing 1.

In a cylindrical bore 22 of the housing 1 there is rotatably inserted a plug 21 sealed by means of a gasket ring 23. On the non-rotating shaft 16 extending through the plug 21, there is arranged a gasket ring 24, a collar 25, a spring 26 and a clamp lever 19.

The spring 26 arranged between the collar 25 and the clamp lever 19 causes the gasket ring 24 located in a conical recess of the collar 25, to seal the non-rotating shaft 16 against the plug 21, and the plug 21 to press against a sealing ring 27 and the underface of the diskshaped portion 14 to bear against a plane gliding surface 28, which is in the interior of the cup-shaped body 6.

The plug 21 is provided with a through bore 29 which forms a connection between the non-rotating shaft 16 and a grooved clearance 31 (FIG. 2) in the plug 21, and a cylindrical bore 33 (FIG. 1) communicating with theoil supply 32. The non-rotating shaft 16 is formed externally with a spiral lubricant elevating groove 30.

Furthermore, the plug 21 is provided with radially arranged bores 24 for inserting a tool, in order to turn the plug 21 in such a manner that more or less oil flows through the duct 29 by varying the cross-sectional area of passage (FIG. 2).

The looptaker shaft 3 is driven by a spiral gear 35 which meshes with a driven spiral gear 36, secured to the looptaker shaft 3.

The oil drawn from the oil supply 32 to the looptaker 4 and emerging between the plane gliding surface 28 and the disk-shaped portion 14, is received by the feltring 11 and arrives via the wick 12 to the annular raceway 7 for the thread case 8.

Excess oil which cannot be received by the felt ring 11, can flow through the return bores 37 into the interior of the housing 1.

What I claim is:

1. In a sewing machine, in combination, a vertical axis rotary looptaker comprising a cup-shaped body having an annular raceway, an annular groove at the bottom of said cup-shaped body, a felt ring received in said annular groove, a duct between said annular groove and said annular raceway, and a wick within said duct, a looptaker shaft secured to said cup-shaped body and formed with a lengthwise bore, a housing journaling said looptaker shaft in said sewing machine and having an oil supply, a driving shaft passing through said housing, gears operatively connecting said driving shaft with said looptaker shaft, a thread case provided with a peripheral bearing rib for receiving in said annular raceway of said cup-shaped body and having a rotation restraining notch in the bottom of said thread case, a thread case rotation restraining member consisting of an upstanding nose cooperating with said rotating restraining notch and formed on a plate occupying a position within said cup-shaped body, a shaft integrally formed with said plate and joumaled in said bore of said looptaker shaft, and a clamp lever secured to the free end of said shaft and slidably received on a pin arranged on the bottom of said housing to effect a non-rotating of said shaft within said looptaker shaft, lubricating means for elevating oil from said oil supply to said annular raceway of said cup-shaped body consisting of spiral lubricant elevating groove formed externally on said shaft, and regulating means for adjusting the delivery of oil to said raceway, comprising a plug adjustably received in a cylindrical bore of said housing and surrounding said shaft of said restraining member, said plug having a grooved clearance formed at a part of the peripheral area of said plug and provided with a reduction of cross-sectional area from a maximum sectional area at one end to a zero sectional area at the other end of said clearance and a through bore ending in said grooved clearance for the passage of oil to said spiral lubricant elevating groove of said shaft, and a spring situated between said collar and said clamp lever, for pressing said collar and said gasket ring against said plug, and said plate of said restraining member against a plane gliding surface of said cupshaped body. 

1. In a sewing machine, in combination, a vertical axis rotary looptaker comprising a cup-shaped body having an annular raceway, an annular groove at the bottom of said cup-shaped body, a felt ring received in said annular groove, a duct between said annular groove and said annular raceway, and a wick within said duct, a looptaker shaft secured to said cup-shaped body and formed with a lengthwise bore, a housing journaling said looptaker shaft in said sewing machine and having an oil supply, a driving shaft passing through said housing, gears operatively connecting said driving shaft with said looptaker shaft, a thread case provided with a peripheral bearing rib for receiving in said annular raceway of said cup-shaped body and having a rotation restraining notch in the bottom of said thread case, a thread case rotation restraining member consisting of an upstanding nose cooperating with said rotating restraining notch and formed on a plate occupying a position within said cup-shaped body, a shaft integrally formed with said plate and journaled in said bore of said looptaker shaft, and a clamp lever secured to the free end of said shaft and slidably received on a pin arranged on the bottom of said housing to effect a non-rotating of said shaft within said looptaker shaft, lubricating means for elevating oil from said oil supply to said annular raceway of said cup-shaped body consisting of spiral lubricant elevating groove formed externally on said shaft, and regulating means for adjusting the delivery of oil to said raceway, comprising a plug adjustably received in a cylindrical bore of said housing and surrounding said shaft of said restraining member, said plug having a grooved clearance formed at a part of the peripheral area of said plug and provided with a reduction of cross-sectional area from a maximum sectional area at one end to a zero sectional area at the other end of said clearance and a through bore ending in said grooved clearance for the passage of oil to said spiral lubricant elevating groove of said shaft, and a spring situated between said collar and said clamp lever, for pressing said collar and said gasket ring against said plug, and said plate of said restraining member against a plane gliding surface of said cupshaped body. 